1. Field of the Invention
The present invention relates to a digital wireless telephone system, and more particularly to a digital wireless telephone system, in which a mobile station is improved in efficiency of the intermittent reception operation in its standby mode reducing power consumption.
2. Description of the Related Art
In the digital wireless telephone system, since the mobile station uses a battery as its own power source, it is very important for the mobile station to reduce its power consumption. In this connection, various types of techniques have been developed to reduce the power consumption of the mobile station. Of these techniques, a so-called battery saving technique has been widely used, in which technique the mobile station has its reception portion intermittently operated in its standby mode to reduce its power consumption. FIG. 8(a) shows a conventional intermittent reception operation of the mobile station in its standby mode. Transmitted at predetermined time intervals in a sending signal used in the conventional intermittent reception operation of the mobile station are time slots each containing paging information of the mobile station. The reception portion of the mobile station has its own power source turned on in timed relationship with paging channels (i.e., P); and turned off in the remaining period of time. For example, in the Digital Mobile-Phone System Standards (i.e., RCR STD-27) prepared by the Denpa Sangyo kai (i.e., ARIB), there is stipulated the intermittent reception operation of the mobile station for saving its battery power in the standby mode in a radio zone. An interval used in such intermittent reception operation stipulated in the above Standards is equal to one superframe interval (i.e., 720 milliseconds) at maximum.
However, in the conventional intermittent reception operation with such one superframe interval at maximum, it is not possible to increase a continuous standby period of time, and, therefore often not possible to increase the efficiency of the intermittent reception operation. Further, the conventional intermittent reception operation with such one superframe interval at maximum is disadvantageous in that it can not set arbitrarily the continuous standby period of time.
Under such circumstances, the present invention was made. Consequently, it is an object of the present invention to provide a digital wireless telephone system, in which the interval in an intermittent reception operation of a mobile station is increased, so that a continuous standby period of time of the mobile station is increased to reduce power consumption of the mobile station.
According to a first aspect of the present invention, the above object of the present invention is accomplished by providing:
In a digital wireless telephone system comprising a mobile station provided with a reception portion, which portion is timed in its turning-on-power operation to a paging channel contained in a sending signal issued from a telephone exchange to the mobile station through a base station, and is held in its de-energized state in the remaining period of time, the improvement wherein:
when an intermittent standby operation is available, the telephone exchange sends out a paging message in an intermittent superframe reception group and in a paging channel group, for which groups the mobile station is waiting; and
the mobile station receives broadcast information, specifies an intermittent reception group on the basis of the contents of intermittent standby information contained in the broadcast information, and performs its intermittent standby reception operation in the reception group having been thus specified.
In the digital wireless telephone system having the above construction, the mobile station performs the intermittent standby reception operation based on the intermittent standby information contained in the broadcast information having been received by the mobile station, so that the interval in such intermittent reception operation is increased, whereby the continuous standby period of time of the mobile station is also increased so as to reduce the power consumption of the mobile station.
According to a second aspect of the present invention, the above object of the present invention is accomplished by providing:
The digital wireless telephone system as set forth in the first aspect of the present invention, wherein the telephone exchange comprises:
an intermittent reception extension information setting means for setting the contents of intermittent standby information in an extension information element contained in the broadcast information;
a subscriber""s information discriminating means for discriminating subscriber""s information;
an intermittent reception group analyzing means for analyzing the intermittent reception group of the mobile station, on the basis of a discrimination result obtained from the subscriber""s information discriminating means and of the intermittent standby information having been set by the intermittent reception extension information setting means; and
a message sending means for sending out the paging message in an intermittent reception group and the paging channel group, for which groups the mobile station is waiting.
The digital wireless telephone system having the above construction is preferable in that the mobile station performs the intermittent standby reception operation based on the intermittent standby information contained in the broadcast information having been received by the mobile station to further increase the interval in such intermittent reception operation.
According to a third aspect of the present invention, the above object of the present invention is accomplished by providing:
The digital wireless telephone system as set forth in the first aspect of the present invention, wherein
defined as the contents of intermittent standby information in the broadcast information are:
an extension information element length; and
an intermittent standby information element comprising an intermittent standby superframe interval and an intermittent standby superframe counter.
The digital wireless telephone system having the above construction is preferable in that the system is capable of arbitrarily setting the interval in the intermittent standby operation of the mobile station, and also capable of performing both synchronization and compensation of such interval.
According to a fourth aspect of the present invention, the above object of the present invention is accomplished by providing:
In a digital wireless telephone system comprising a mobile station provided with a reception portion, which portion is timed in its turning-on-power operation to a paging channel contained in a sending signal issued from a telephone exchange to the mobile station through a base station, and is held in its de-energized state in the remaining period of time, the improvement wherein:
the telephone exchange retrieves both of location information and subscriber""s information from a subscriber""s information memory, and sends out a paging message in both an intermittent superframe reception group and a paging channel group, for which groups the mobile station is waiting; and
the mobile station receives broadcast information, specifies an intermittent reception group on the basis of an intermittent standby superframe interval having been set in its own unit by means of an intermittent standby superframe counter, and performs its intermittent standby reception operation in the reception group having been thus specified.
In the digital wireless telephone system having the above construction, the mobile station uses the intermittent standby superframe counter contained in the broadcast information, specifies the intermittent reception group on the basis of the intermittent standby superframe interval having been set in its own unit, and performs the intermittent standby reception operation in the reception group thus specified, which enables the system to increase the interval in the intermittent reception operation of the mobile station without providing in its subscriber""s information memory any information indicating whether or not the mobile station is adapted to perform a high-efficiency operation, whereby the continuous standby period of time of the mobile station is increased, and the mobile station has its power consumption decreased.
According to a fifth aspect of the present invention, the above object of the present invention is accomplished by providing:
The digital wireless telephone system as set forth in the fourth aspect of the present invention, wherein:
the telephone exchange comprises:
a Cs information setting means for setting an intermittent standby superframe counter information element in an extension information element contained in the broadcast information;
an intermittent reception group analyzing means for analyzing the intermittent reception group of the mobile station, on the basis of the location information and the subscriber""s information both retrieved from a subscriber""s information memory; and
a message sending means for sending out the paging message in the intermittent superframe reception group and the paging channel group, for which groups the mobile station is waiting;
while the mobile station comprises:
a Pi memory means for recording the intermittent standby superframe interval.
The digital wireless telephone system having the above construction is preferable in that the mobile station receives the broadcast information, uses the intermittent standby superframe counter contained in the broadcast information, and performs the intermittent standby reception operation at the intermittent standby superframe intervals of its own unit.
According to a sixth aspect of the present invention, the above object of the present invention is accomplished by providing:
In a digital wireless telephone system comprising a mobile station provided with a reception portion, which portion is timed in its turning-on-power operation to a paging channel contained in a sending signal issued from a telephone exchange to the mobile station through a base station, and is held in its de-energized state in the remaining period of time, the improvement wherein:
the telephone exchange retrieves both of location information and subscriber""s information from a subscriber""s information memory, and continuously sends out an inter-superframe paging message in a paging channel group, for which groups the mobile station is waiting, the number of the inter-superframe paging messages being the same value as that of intermittent standby superframe intervals; and
the mobile station receives broadcast information, and performs its intermittent standby reception operation, on the basis of both the broadcast information and the contents of intermittent standby information which contains the intermittent standby superframe interval having been set in its own unit.
In the digital wireless telephone system having the above construction, the mobile station is capable of performing, without involving any delay time, the high-efficiency intermittent reception operation in the paging messages thus continuously transmitted, on the basis of both the broadcast information and the intermittent standby information having been set in its own unit.
According to a seventh aspect of the present invention, the above object of the present invention is accomplished by providing:
The digital wireless telephone system as set forth in the sixth aspect of the present invention, wherein:
the telephone exchange comprises:
a PCH group analyzing means for analyzing the paging channel group, for which group the mobile station is waiting, on the basis of the location information and the subscriber""s information both retrieved from a subscriber""s information memory; and
a message continuously sending out means for continuously sending out an inter-superframe paging message in a paging channel group, for which group the mobile station is waiting, the number of the inter-superframe paging messages being the same value as that of intermittent standby superframe intervals;
while the mobile station comprises:
an intermittent reception information memory means for recording the contents of intermittent standby information containing the intermittent standby superframe interval.
The digital wireless telephone system having the above construction is preferable in that the mobile station receives the broadcast information, uses the intermittent standby information having been set in its own unit, and performs the intermittent standby reception operation so that the interval in such intermittent reception operation is further increased.
According to an eighth aspect of the present invention, the above object of the present invention is accomplished by providing:
In a digital wireless telephone system comprising a mobile station provided with a reception portion, which portion is timed in its turning-on-power operation to a paging channel contained in a sending signal issued from a telephone exchange to the mobile station through a base station, and is held in its de-energized state in the remaining period of time, the improvement wherein:
the telephone exchange retrieves both of location information and subscriber""s information from a subscriber""s information memory, and continuously sends out an inter-superframe paging message in a paging channel group, for which groups the mobile station is waiting, the number of the inter-superframe paging messages being the same value as that of intermittent standby superframe intervals; and
the mobile station receives broadcast information, and performs its intermittent standby reception operation, on the basis of the intermittent standby superframe interval contained in the broadcast information.
In the digital wireless telephone system having the above construction, the mobile station uses the intermittent standby superframe interval contained in the broadcast information, and performs the intermittent standby operation in the paging messages having been continuously transmitted, which enables the mobile station to performs the high-efficiency intermittent reception operation without involving any delay time.
According to a ninth aspect of the present invention, the above object of the present invention is accomplished by providing:
The digital wireless telephone system as set forth in the eighth aspect of the present invention, wherein:
the telephone exchange comprises:
a Pi information setting means for setting the intermittent standby superframe interval information element in an extension information element contained in the broadcast information;
a PCH group analyzing means for analyzing the paging channel group, for which group the mobile station is waiting, on the basis of the location information and the subscriber""s information both retrieved from a subscriber""s information memory; and
a message continuously sending out means for continuously sending out an inter-superframe paging message in a paging channel group, for which group the mobile station is waiting, the number of the inter-superframe paging messages being the same value as that of the intermittent standby superframe intervals.
The digital wireless telephone system having the above construction is preferable in that the mobile station receives the intermittent standby superframe interval contained in the broadcast information, and performs the intermittent standby reception operation so that the interval in such intermittent reception operation is further increased.
According to a tenth aspect of the present invention, the above object of the present invention is accomplished by providing:
The digital wireless telephone system as set forth in the first aspect of the present invention, wherein:
in intermittent reception state, the mobile station measures a perch channel in a peripheral zone after completion of reception of the paging channel in timing, the number of the peripheral zones to be measured being the same value as that of the intermittent standby superframe intervals.
The digital wireless telephone system having the above construction is preferable in that the perch channel in the peripheral zones is measured in timed relationship with the intermittent reception operation.
According to an eleventh aspect of the present invention, the above object of the present invention is accomplished by providing:
The digital wireless telephone system as set forth in the first aspect of the present invention, wherein:
in intermittent reception state, the mobile station measures a perch channel in a peripheral zone each time a superframe appears.
The digital wireless telephone system having the above construction is preferable in that the perch channel in the peripheral zones is measured in timed relationship with the intermittent reception operation.
According to a twelfth aspect of the present invention, the above object of the present invention is accomplished by providing:
The digital wireless telephone system as set forth in first aspect of the present invention, wherein,
the mobile station measures a bit error rate and a level of reception, and performs its high efficiency intermittent reception when both of said bit error rate and said level of reception have reached a prescribed value for a prescribed period of time. Each mobile station measures the bit error rate (hereinafter called BER) and the level of reception each time a superframe appears. The mobile station also has a counter that counts if both of the BER and the reception level values have reached prescribed values and lasts until the next superframe appears. Alternatively, the mobile station comprises two counters, a first counter which advances when the BER reaches a prescribed value and lasts for one superframe (i.e. until the next superframe appears), and a second counter which advances when the level of reception reaches a prescribed value and also lasts for one superframe.
According to a thirteenth aspect of the present invention, the above object of the present invention is accomplished by providing:
The digital wireless telephone system as set forth in the first aspect of the present invention, wherein,
in high efficiency intermittent reception, the mobile station measures a bit error rate and a level of reception, and stops its high efficiency intermittent reception and performs ordinary intermittent reception when either said bit error rate or said level of reception fail to reach a prescribed value for a prescribed period of time.